Database Reference
In-Depth Information
Figure 10.20. Example of a self-referencing one-to-one relationship
Figure 10.21
shows how you diagram this type of relationship.
Figure 10.21. Diagramming a self-referencing one-to-one relationship
One-to-Many
A table bears a
self-referencing one-to-many
relationship to itself when a given record in
the table can be related to one or more other records within the table.
Figure 10.22
shows
an example in which a given customer can refer other customers to the organization. The
R
EFERRED
B
Y
field stores the customer identification number of the customer making the
referral. Note that Paul Litwin referred both Andy Baron and Mary Chipman.
